Retaining element and method of mounting lines

ABSTRACT

The invention relates to a retaining element of plastic having a captive fastening part located therein and to a method of mounting lines on an article. In this case, the retaining element has at least one line receptacle, at least one cavity for the captive accommodation of a fastening part, at least two pivotable tongues in the wall of the cavity, with in each case a retaining member directed into the cavity and intended for accommodating a radially projecting section of the fastening part in a preassembly position, a tool entry opening of the cavity, and a bearing surface, serving as final assembly position, on the bottom of the cavity. The cavity is preferably formed by three finger-like catch hooks.

The invention relates to a retaining element of plastic having afastening part located therein and to a method of mounting lines onarticles.

The mounting of lines, such as pipes and cables, on a foundation bymeans of clips is expensive and requires complicated working steps.Often, to fasten lines and the like, first of all threaded bolts or thelike are attached to an article. A fitter in each case puts a plasticclip onto a threaded bolt. The lines and a mating part are then put ontothe clip. Further rationalization of these operations is problematic,since the sequence of operations has to be maintained. In addition, amultiplicity of parts have to be manipulated.

An aim of the present invention is to provide a retaining element ofplastic and a method for simplified mounting of lines, such as, forexample, electric cables, pipes and the like.

This aim is achieved with a retaining element and a method as defined inthe claims, the subclaims representing expedient developments.

Accordingly, a retaining element of plastic having at least one linereceptacle and a cavity for the captive accommodation of a fasteningpart is provided. The fastening is no longer effected on retainingdevices attached beforehand, such as threaded bolts for example. Thefastening part is preferably made of metal and in particular ispreferably designed as a screw.

The hole- and thread-forming screw presented in DE 39 09 725 C1 forscrewing into sheet metal of a thickness up to about 1 mm is especiallysuitable as fastening part for fastening the retaining element accordingto the invention. Such a screw has a head having a tool receptacle, athreaded shank and an adjoining cylindrical part which is of a diameterlying below the effective diameter of the threaded shank and merges intoa tapering hole-forming part. In this case, the threaded shank mergesinto the cylindrical part via a taper extending over about four threadturns. The hole-forming part ends in a crowned friction surface whichcorresponds to a radius of about 0.5 mm. Especially firm seating can beachieved with such a hole- and thread-forming screw, the accumulation ofmetal chips, which could fall into the hole produced, being avoided atthe same time.

The fastening part is in particular preferably enclosed in the radialdirection over its entire length by the retaining element and thereforedoes not project axially beyond the latter. Risk of injury due to aprojecting point of the fastening part is thus avoided. The position ofthe preassembled fastening part can no longer be changed from outside,for example during transport. Since it is thus not possible for thefront end (point) of the fastening part to project, plane-parallelbearing of the retaining element against an article can be achievedwithout the retaining element being distorted during assembly. This isespecially important when a plurality of fastening parts which couldotherwise project from the retaining element with their points areprovided for attaching the retaining element to the article.

In a modification of the invention, the cavity is laterally open. Inparticular, at least two, preferably at least three, and preferablythree openings are provided. These openings may be designed likewindows. These openings are preferably designed in such a way that theyrun up to the free margin of the cavity. In this way, the cavity isdefined by finger-like projections, there being at least two, butpreferably three of such finger-like projections. These finger-likeprojections are preferably of symmetrical design and arranged around thecavity.

In this modification, the invention thus relates to a retaining elementof plastic in which the cavity is formed by a wall provided withopenings.

In this case, the wall provided with openings is preferably formed fromat least two, preferably at least three, and in particular preferablythree finger-like projections. For effective retention of the fasteningpart, the finger-like projections, in the region facing the cavity, areprovided with an extension having a groove-like section for retainingthe fastening part.

The retaining element is preferably designed in such a way that thefinger-like projections are approximately as long as the fastening part.

This modification of the invention therefore represents a retainingelement of plastic, in particular one as described above for mountinglines on an article, which retaining element has:

a. at least one line receptacle,

b. at least one location region formed from at least two finger-likeprojections and intended for the captive accommodation of a fasteningpart,

c. a retaining location device located in the location region andintended for accommodating and retaining the fastening part in apreassembly position,

d. a tool entry opening of the location region on that side of theretaining element which is remote from the article,

e. a bearing surface, serving as final assembly position, on the bottomof the location region for a head of the fastening part.

The fastening of the retaining element according to the invention doesnot require the same precision as the placing of a clip at a point whichis exactly predetermined, for example by an attached threaded bolt.Simple assembly is possible on account of the fastening part captivelypreassembled in the retaining element. No mating part has to be put ontoa first clip. It is merely necessary to slip the retaining element ontoone or more lines, to place this system in position and to anchor thefastening part to the relevant article. Apart from the lines to befastened and having retaining elements, no further part has to be moved.On account of the simple working steps and the reduced requirement forprecision during assembly, the system is readily suitable not only formanual assembly but also for semi-automatic or fully automatic assembly.The preassembled system, consisting of the lines with retaining elementsattached thereto, can be delivered from suppliers to the manufacturer soas to suit a corresponding article, e.g. lines fitted with retainingelements for the cooling unit of a refrigerator. At the manufacturer's,the system need only be placed in position on the article and fastenedor screwed thereto.

Further advantages, features and possible uses of the present inventionfollow from the description below of an exemplary embodiment incombination with the drawings, in which preferred embodiments andfeatures of the invention are shown and:

FIG. 1 shows a retaining element bearing against a foundation,

FIG. 2 shows a section through the cavity of the retaining element ofFIG. 1,

FIG. 3 shows a plan view of the cavity of the retaining element,

FIG. 4 shows a section through the cavity of the retaining element whenthe fastening screw is being screwed into place,

FIG. 5 shows a section through the cavity of the retaining elementfastened to the foundation,

FIG. 6 shows pipelines attached to an article,

FIGS. 7 and 8 show a modified embodiment of the retaining elementaccording to the invention.

A retaining element 1 bearing on a sheet-metal foundation or article 5is shown in FIG. 1. The retaining element has 2 line receptacles 11,which are provided with an elastic coating, for example a thermoplasticelastomer, rubber, silicone or the like, in the inner region. Such anelastic coating absorbs vibrations which otherwise would be transmittedby a line, in particular from a pump operation, to the article. Acentral cavity 12 of the retaining element is provided for accommodatinga fastening part. A retaining location device 20 formed axially in thewall of the cavity 12 with respect to the fastening part to be insertedserves to accommodate the fastening part in a preassembly position. Theretaining location device is shaped as a tongue.

FIG. 2 shows a section through the cavity 12. A fastening part 7designed as a screw is held in a preassembly position by tongues 20. Tothis end, a pressure washer extending radially beyond the head from theshank of the screw 7 is snapped into a groove 16 of the retainingmembers 13 of the tongues 20. Due to the one-piece design of a tongue 20with the wall of the cavity 12, a prestress which is adequate for thecaptive retention of the fastening part 7 is applied. The fasteningscrew is not removed from its preassembly position even by vibrations,as occur during transport.

The retaining element 1 is configured in such a way that the fasteningpart 7 is enclosed axially by the retaining element. Therefore neitherpoint nor head projects from the retaining element or the cavity 12.

The tool entry opening 14 is bevelled, so that it widens outwards or thewall of the cavity 12 tapers. In this way, a tool to be inserted intothe tool entry opening 14 is centred. This is especially helpful when atool is to be inserted automatically into the cavity 12 of the retainingelement.

That end section 17 of the tongue 20 which faces the tool entry opening14 is designed as a projection directed into the cavity in order toaccommodate the fastening part in a preassembly position and tapers inthe direction of the tool entry opening 14 on its side facing theinterior of the cavity 12. This end section 17, designed as an inclinedplane, enables a tool penetrating into the cavity 12 or the fasteningpart 7 itself to expand the hook-like tongues 20 in opposition to theirprestress and put the fastening part into its preassembly position andsubsequently into the separate final assembly position from itspreassembly position.

FIG. 3 shows a plan view of the cavity 12. It can be seen that thecavity 12 accommodates two retaining members 13 and consequently twotongues 20. The retaining members 13 are designed as inwardly directed,snap-hook-like projections having an encircling groove 16 on theirinside.

FIG. 4 shows a driving tool coming into action in the cavity 12. Whenpenetrating into the cavity 12, the tool, which is designed as a socketspanner, acts on the tapering end sections 17 of the retaining members13 and spreads the tongues 20 apart upon further penetration, takes holdof the head of the screw 7 in the preassembly position and pushes thescrew in the direction of the final assembly position for screwing intothe foundation 5. In the preassembly position, the screw is located withits front end in a metal bush 6. The metal bush ensures that asufficiently large prestress can be applied with the fastening part 7for very good service life.

The fastening screw 7 has a conical hole-forming part. The cone hassymmetrically arranged flats, as described in DE 39 09 725 C1. Thisensures that the point or the front section of the screw 7, in a quickand reliable manner, creates a nozzle-shaped opening in the sheet-metalfoundation, in which a thread is formed by the adjoining threadedsection. Preliminary perforation in an article or a preassembledfastening member, such as, for example, an attached threaded bolt or thelike, can be dispensed with.

FIG. 5 shows the screw 7 in its final assembly position. It rests withits head on the bearing surface 15 formed by the metal bush 6. In thiscase, the pressure washer 8 of the head, which projects radiallyrelative to the tool application section of the head, permits anespecially favourable distribution of the forces over a larger area. Atthe same time, the pressure washer 8 can serve not only to retain thescrew in the preassembly position but also as a stop for guiding thescrew by a tool.

When being screwed into place, the screw head deforms a sealing lip 18,which surrounds the screw head in a sealing manner. Ingress of moistureinto the sheet-metal foundation is thus reliably avoided.

The insertion of the fastening part 7 into the foundation 5 is notdisturbed by lines, since the cavity 12, which accommodates thefastening part 7, is designed to be separate from one or more linereceptacles of the retaining element 1. Line receptacle 11 and cavity 12are arranged to be offset perpendicularly to the direction of fastening.A line is clipped, snapped or clamped into a line receptacle in acaptive manner.

FIG. 6 shows pipelines 2 which are anchored on a sheet-metal foundation5 by the retaining element 1. The retaining element is fastened to thefoundation by means of a hole- and thread-forming screw.

Three finger-like projections or catch hooks 21 are provided in themodification, shown in FIGS. 7 and 8, of the retaining element accordingto the invention. These catch hooks 21 project axially from a base ring25, which also guides the point of the screw 7. The catch hooks haveextensions 24 on their inside and in the region of the free end, theseextensions 24 having recesses 23, in which, for example, an annularregion of a screw head is retained. For the captive retention of afastening part, e.g. a screw 7, the finger-like projections or catchhooks need only be bent slightly outwards. This operation may beautomated in a simple manner. The extensions 24 are preferably providedwith a bevel 26, which is directed inwards and facilitates the insertionof the fastening part 7.

The retaining element of this modification is also preferablyinjection-moulded in one piece from plastic.

List of Reference Numerals

1 Retaining element

2 Pipeline

3 Foundation

4 Metal bush

7 Fastening part

8 Pressure washer of the fastening part

11 Line receptacle of the retaining element

12 Cavity of the retaining element

13 Retaining member for the preassembly of the fastening part

14 Tool entry opening

15 Bearing surface for the final assembly of the fastening part

16 Groove

17 End section of the retaining member

18 Sealing lip

19 Elastic coating in the line receptacle

20 Pivotable tongue

21 Finger-like catch hooks

22 Openings

23 Groove-like section

24 Extension

25 Base ring

26 Bevel

What is claimed is:
 1. Retaining element of plastic for mounting lineson an article and adapted for use with a fastening part by which theretaining element may be secured to an article which retaining elementhas: a. at least one line receptacle (11); b. at least one cavity (12)for the captive accommodation of a fastening part (7); c. a retaininglocation device (13, 20) located in the cavity and intended foraccommodating and retaining a fastening part (7) in a preassemblyposition in such a way that a fastening part (7) does not project beyondthe retaining element in the axial direction; d. a tool entry opening(14) of the cavity (12) on that side of the retaining element which isremote from the article; e. a bearing surface (15), serving as finalassembly position, on the bottom of the cavity (12) for a head of afastening part; and f. characterized in that, when a fastening part (7)is pushed axially into its pre-assembly position, the retaining locationdevice (20) exerts a radial prestress, which is at least partly relievedin the pre-assembly position.
 2. Retaining element according to claim 1,characterized in that the retaining location device has at least 2pivotable tongues (20) in the wall of the cavity (12), with in each casea retaining member (13) directed into the cavity and intended foraccommodating a radially projecting section (8) of a fastening part (7)in a preassembly position.
 3. Retaining element according to claim 2,characterized in that the retaining member (13) is designed as aprojection directed into the cavity.
 4. Retaining element of plastic formounting lines on an article and adapted for use with a fastening partby which the retaining element may be secured to an article whichretaining element has: a. at least one line receptacle (11); b. at leastone cavity (12) for the captive accommodation of a fastening part (7);c. a retaining location device (13,20) located in the cavity andintended for accommodating and retaining a fastening part (7) in apreassembly position in such a way that a fastening part (7) does notproject beyond the retaining element in the axial direction,characterized in that the retaining location device (13,20) has at leasttwo pivotal tongues (20) in the wall of the cavity (12), with in eachcase a retaining member (13) directed into the cavity and intended foraccommodating a radially projecting section (8) of a fastening part (7)in a preassembly position; d. a tool entry opening (14) of the cavity(12) on that side of the retaining element which is remote from thearticle; e. a bearing surface (15), serving as a final assemblyposition, on the bottom the cavity (12) for a head of a fastening part;f. the retaining member (13) being designed as a projection directedinto the cavity (12); and g. further characterized in that a groove (16)running radially relative to a fastening part (7) is formed on that sideof the retaining member (13) which is directed into the cavity (12). 5.Retaining element according to claim 3, characterized in that that endsection (17) of the retaining member (13) which faces the tool entryopening (14) tapers in the direction of the tool entry opening on itsside directed into the interior of the cavity (12).
 6. Retaining elementaccording to claim 3, characterized in that the tool entry opening (14)widens in the direction of the side remote from the bearing surface(15).
 7. Retaining element according to claim 3, characterized by ametal bush (6) in the bottom of the cavity (12), which metal bush (6) isintended for bearing on the article (5).
 8. Retaining element accordingto claim 1, characterized by a radial sealing lip (18), which is in onepiece with the retaining element (1) and encircles the bearing surface(15) for a fastening part (7) in such a way that the head of a fasteningpart is surrounded in a sealing manner after the final assembly. 9.Retaining element of plastic for mounting lines on an article andadapted for use with a fastening part by which the retaining element maybe secured to an article which retaining element has: a. at least oneline receptacle (11); b. at least one cavity (12) for the captiveaccommodation of a fastening part (7); c. a retaining location device(13, 20) located in the cavity and intended for accommodating andretaining a fastening part (7) in a preassembly position in such a waythat a fastening part (7) does not project beyond the retaining elementin the axial direction; d. a tool entry opening (14) of the cavity (12)on that side of the retaining element which is remote from the article;e. a bearing surface (15), serving as final assembly position, on thebottom of the cavity (12) for a head of a fastening part; and f. aradial sealing lip (18), which is in one piece with the retainingelement (1) and encircles the bearing surface (15) for a fastening part(7) in such a way that the head of a fastening part is surrounded in asealing manner after the final assembly, the sealing lip (18), startingfrom a base at the bottom of the cavity (12), tapers in the direction ofthe tool entry opening (14), at least a base of the sealing lipprojecting under the head of a fastening part (7).
 10. Retaining elementaccording to claim 1, characterized in that the line receptacle (11) isdesigned as a clamp for the captive attachment of the retaining element(1) to a line.
 11. Retaining element according to claim 1, characterizedin that the line receptacle (11) is lined with an elastic material (19).12. Retaining element according to claim 3, further including afastening part and characterized in that the fastening part (7) isdesigned as a hole- and thread-forming screw for screwing into the sheetmetal, having a head, a threaded shank and a tapering hole-forming part.13. Retaining element according to claim 3, characterized in that afastening part (7) is fully enclosed axially by the retaining element(1) in its preassembly position.
 14. Retaining element of plasticaccording to claim 3, characterized in that the cavity (12) is formed bya wall provided with openings (22).
 15. Retaining element of plasticaccording to claim 14, characterized in that the wall provided withopenings (22) is formed from a plurality of finger-like projections(21).
 16. Retaining element of plastic for mounting lines on an articleand adapted for use with a fastening part by which the retaining elementmay be secured to an article which retaining element has: a. at leastone line receptacle (11); b. at least one cavity (12) for the captiveaccommodation of a fastening part (7); c. a retaining location device(13, 20) located in the cavity and intended for accommodating andretaining a fastening part (7) in a preassembly position in such a waythat the fastening part (7) does not project beyond the retainingelement in the axial direction; d. a tool entry opening (14) of thecavity (12) on that side of the retaining element which is remote fromthe article; e. a bearing surface (15), serving as final assemblyposition, on the bottom of the cavity (12) for a head of [the] afastening part; and f. a cavity (12) being formed by a wall providedwith openings, the openings (22) being formed from a plurality offinger-like projections (21), the finger-like projections (21), in theregion facing the cavity having an extension (24) provided with agroove-like section (23) for retaining a fastening part (7). 17.Retaining element of plastic of mounting lines on an article and adaptedfor use with a fastening part by which the retaining element may besecured to an article which retaining element has: a. at least one linereceptacle (11); b. at least one cavity (12) for the captiveaccommodation of a fastening part (7); c. a retaining location device(13,20) located in the cavity and intended for accommodating andretaining a fastening part (7) does not project beyond the retainingelement in the axial direction; d. a tool entry opening (14) of thecavity (12) on that side of the retaining element which is remote fromthe article; e. a bearing surface (15), serving as final assemblyposition, on the bottom of the cavity (12) for a head of a fasteningpart; f. characterized in that the cavity (12) is formed by a wallproviding with openings (22) which in turn is formed from a plurality offinger-like projections (21); and g. further including a fastening partin said cavity and characterized in that the finger-like projections(21) are approximately as long as the fastening part (7).
 18. A plastic,line mounting retaining element for mounting lines on another article,comprising: a plastic retaining element body; at least one linereceiving receptacle in said body for receiving a line to be mounted onanother article; at least one fastening part cavity in said body and ofa size to wholly receive a fastening part; a fastening part in saidcavity, said fastening part including an enlarged head and a narrowershank depending therefrom, and being entirely within said cavity andmovable relative to said body such that said shank may extend from saidbody to secure said body to another article; a fastening part retainingstructure within said cavity resiliently engaging said head toreleasably hold said retaining part at a predetermined position withinsaid cavity; a tool entry opening to said cavity adjacent said head toallow said head to be engaged by a tool; and a bearing surface in saidcavity oppositely of said tool entry opening and positioned to beabutted by said head when said shank is fully extended from said body.